Update on Epidemiology of IgG4-related Disease Involving the Liver and Pancreas

IgG4-related disease (IgG4-RD) is a rare condition characterized by an immune-mediated fibro-inflammation affecting various organs (liver, pancreas, heart, kidney, brain among others) with peculiar histopathologic feature. Few epidemiological data have been published so far, although a dramatic increase in the number of patients diagnosed with IgG4-RD has been recorded in the last years. The clinical manifestations of IgG4-RD involve frequently liver and pancreas. Specifically, a crucial challenge in differential diagnosis is IgG4-related sclerosing cholangitis which is frequently accompanied by pancreatic involvement. Inflammatory alterations of liver parenchyma have also been described, with a new nosology of IgG4-autoimmune hepatitis. Type 1 autoimmune pancreatitis is the pancreatic manifestation of the IgG4-RD. The first-ever epidemiological study to estimate the point prevalence of IgG4-related sclerosing cholangitis has been recently conducted in Japan. Moreover, several demographic studies on IgG4-RD involving liver and pancreas have been published in other countries, although the majority of them are cohort studies and data on incidence/prevalence are lacking. This review aims to update the recent epidemiological and clinical knowledge of IgG4-RD involving liver and pancreas, focusing also on the risk of malignancy.